a human limb; technically the part of the superior limb between the shoulder and the elbow but commonly used to refer to the whole superior limb. arm, branch, limb (noun). any projection that is thought to resemble a human arm.
Vertebrates are the most organized organisms on Earth. They belong to the sub-phylum Vertebrata. They are not the most numerous group of animals, they are the most advanced group of animals.The characteristics that makes vertebrates special are the presence of the spinal cords, vertebrae and notochords.hey belong to the Phylum Chordata. The characteristics of phylum chordata is the presence of notochord, a dorsal hollow nerve cord and paired pharyngeal gill slits. The members of subphylum Vertebrata possess notochord during the embryonic period.
Vertebrates are members of the larger phylum Chordata, and show all of the major chordate features at some point in their life cycles: notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.his arch is not present in other vertebrates, which may have lateral spines on the centrum instead of ventral spines. The jawless fish of today, the hagfish and lampreys, lack vertebral centra -- thus they are not vertebrates in the usual sense -- but they have neural arches on their notochords.